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Article
Publication date: 1 January 1994

T. Yamada, J. Barrett, R. Doyle and A. Boetti

The use of Taguchi experimental design techniques to examine the effects of package type, solder paste type and solder reflow technique on the quality of fine pitch…

Abstract

The use of Taguchi experimental design techniques to examine the effects of package type, solder paste type and solder reflow technique on the quality of fine pitch surface mount IC package solder joints is described. In particular, the effect of the use of ceramic or plastic packages, copper or Alloy 42 leadframes, silver loaded or non‐silver loaded solder paste and infra‐red, laser or hot‐bar reflow on solder joint metallurgical structure, electrical resistance and mechanical strength is evaluated. In addition to these solder joint parameters, an associated visual inspection was used to find the best process parameters to minimise solder balling, bridging etc. and a correlation between paste contacts at placement and solder bridges after reflow was also conducted. The experiment used an L9 array to find the optimum parameters from three factors, each at three levels. An extension to the basic Taguchi array was included in the form of an outer (noise) factor to include the effect of climatic stress on the solder joints under investigation. Response tables separate out the contribution of each factor level to the mechanical strength and electrical resistance of the assemblies. By comparing the response tables before and after climatic testing it is possible to estimate the effect of each factor level on the long‐term quality of the solder joints. It is shown how Taguchi experimental design techniques can be used to minimise the number of experiments required to predict optimum solder assembly process parameters. The accuracy of the prediction is shown by the results of a confirmation run which yielded mechanical strengths very close to those predicted, both before and after highly accelerated stress testing of the solder assemblies.

Details

Soldering & Surface Mount Technology, vol. 6 no. 1
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 21 March 2016

Harish Garg and Rupinder Singh

This paper aims to carry out experimental investigations highlighting the role of melt flow index (MFI) in fused deposition modelling (FDM) process by varying the…

Abstract

Purpose

This paper aims to carry out experimental investigations highlighting the role of melt flow index (MFI) in fused deposition modelling (FDM) process by varying the proportion of the Fe powder which is being used as a filler material. An attempt has been made to standardize MFI of Nylon6-Fe composite material to be used as hybrid FDM filament.

Design/methodology/approach

In this research work, it is proposed to make a suitable blend of composite material for FDM filament which can be used directly for rapid tooling applications. Three controllable parameters (namely, composition/proportion of the filler for hybrid filament, extrusion temperature and extrusion load) were studied by using Taguchi L9 orthogonal array (O.A.) MFI which is an indication of flowability has been selected as output parameter.

Findings

MFI of hybrid composite filament material has been studied, and Taguchi’s L9 O.A. was applied under both the conditions of lower the better type and larger the better type. It is observed that the contribution of the extrusion load, extrusion temperature and proportion of the filler material is almost similar, whether lower the better type situation is considered or larger the better type is considered. Further, an attempt has been made to standardize the MFI of Nylon6-Fe composite material for industrial applications, as no standard is available for composites (presently, ASTM-D-1238-95 standard is being used for plastic based materials only).

Originality/value

In recent past, researchers have studied and analysed the flow of the material through the nozzle of the FDM machine, but very little work has been reported on study of the flow characteristics of filament material before the composite material is fed into the machine. This research can open new avenues in the field of MFI and deals with comparison of MFI of the existing FDM feedstock material with the new composite material. The developed feedstock material is ferromagnetic in nature and can find wide variety of industrial applications.

Details

Rapid Prototyping Journal, vol. 22 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 6 April 2021

Kun Liu, Wei Chen, Jihong Ye, Jian Jiang, Wenwen Chen and Mingyue Zhao

Most previous thermal-mechanical modeling of cold-formed steel (CFS) walls did not consider the failure of screwed connections under fire conditions because of the limited…

Abstract

Purpose

Most previous thermal-mechanical modeling of cold-formed steel (CFS) walls did not consider the failure of screwed connections under fire conditions because of the limited data of such connections at elevated temperatures.

Design/methodology/approach

In this study, 285 steady-state tests are conducted on CFS screwed connections with single-layer gypsum plasterboard (GPB) and Bolivian magnesium board (BMB) sheathing at ambient and elevated temperatures. The failure of these connections is described as the breaking of the loaded sheathing edge.

Findings

For the BMB sheathing screwed connections, hydrochloric acid gas is generated and released above 300°C, and the shear strength becomes much less than that of the GPB sheathing screwed connection above 370°C. Hence, BMB may not be suitable for use as the face-layer sheathing of CFS walls but is still recommended to replace GPB as the base-layer sheathing. The major influencing parameters on the shear strength of screwed connections are identified as the type of sheathing material and the loaded sheathing edge distance.

Originality/value

Based on the previous and present test results, a unified expression for the residual shear strength of screwed connections with GPB and BMB is proposed at ambient and elevated temperatures with acceptable accuracy. It can be used as the basic input parameter of the numerical simulation of the CFS structures under fire conditions.

Details

Journal of Structural Fire Engineering, vol. 12 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 1 December 2005

J.P. Kruth, S. Kumar and J. Van Vaerenbergh

To find the suitable parameters for selective laser sintering (SLS) of selected ferro‐based powders. These parameters will help to create products having appreciable…

1257

Abstract

Purpose

To find the suitable parameters for selective laser sintering (SLS) of selected ferro‐based powders. These parameters will help to create products having appreciable strength shown by the highest density and good surface property.

Design/methodology/approach

Design of experiment (L9 Taguchi design) has been used to obtain the parameters in the minimum possible number of experiments. For finding the range of various parameters selected such as scan speed, scan spacing and layer thickness, some preliminary experiments have been performed. In order to carry out varied characterization for a given type of experiment, a number of samples have been made.

Findings

An attempt has been made to observe the correlation between applied laser energy and the properties of the laser‐sintered parts. Taguchi design has been useful and has given the optimized parameters. It has also been found that the infiltration increases the strength of the part substantially compared with the property of end‐used sintered product.

Research limitations/implications

The present set of experiments was limited by the range of supplied laser energy to the powder system, as the laser power could not be increased.

Originality/value

There is a need to search for alternative powders for manufacturing parts through SLS, which can alleviate the need to depend on customized powders, as these customized powders are limited to be used only with prescribed commercial SLS machines for their best performance. This drawback restricts their general use independent of any particular machine and it is, therefore, required to develop know‐how of powders and related process parameters for SLS. The present work is an effort in this direction in which laser sintering of a specially developed iron‐based powder mixture (Fe, Ni, Cu and Fe3P) has been tested on an SLS machine.

Details

Rapid Prototyping Journal, vol. 11 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 22 February 2022

Evelyne Hahang, Secil Bayraktar and Alfredo Jiménez

Given the critical consequences of the current Coronavirus (COVID-19) crisis worldwide, displaying good leadership has been of utmost importance. Hospitality has been…

Abstract

Purpose

Given the critical consequences of the current Coronavirus (COVID-19) crisis worldwide, displaying good leadership has been of utmost importance. Hospitality has been among the industries that have been hit the hardest by the pandemic, and it requires exceptional leadership skills unique to this crisis and sector. This multi-country study aims to contribute to the understanding of some of the most important skills and strategies that leaders in the hospitality industry may use to navigate the COVID-19 crisis effectively.

Design/methodology/approach

This paper employs a qualitative study. Semi-structured interviews are conducted with managers of international hospitality groups or local hotel chains in seven different countries.

Findings

The results show that positive thinking, decision-making, flexibility, divergent thinking, trust-building and communication skills have a positive impact on leadership effectiveness in the hospitality sector during the pandemic. Besides, saving payroll costs, elaborating contingency plans and leveraging from partners' strengths are highlighted as crucial strategies.

Practical implications

This paper provides hospitality professionals across borders preliminary insights and recommendations to manage the COVID-19 crisis.

Originality/value

Especially being one of the sectors that have been hit the hardest by the COVID-19 crisis worldwide, the dynamics and leadership requirements of the hospitality sector need further attention. The findings contribute to the literature by illustrating how managers have navigated the initial stages of the crisis in the under-researched hotel sector, and also by gathering evidence about the sector dynamics related to the early stages of this crisis.

Details

Cross Cultural & Strategic Management, vol. 29 no. 3
Type: Research Article
ISSN: 2059-5794

Keywords

Article
Publication date: 31 August 2021

Nitin Dixit, Varun Sharma and Pradeep Kumar

The surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts…

Abstract

Purpose

The surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM).

Design/methodology/approach

A hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa).

Findings

The developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts.

Practical implications

The FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study.

Research limitations/implications

The present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques.

Originality/value

An abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.

Details

Rapid Prototyping Journal, vol. 28 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 21 May 2020

Nitin Kumar Gupta, Gananath Doulat Thakre and Manoj Kumar

The purpose of this study is to investigate the tribological performance of the developed self-healing Al6061 composite and to optimize the operating conditions for…

Abstract

Purpose

The purpose of this study is to investigate the tribological performance of the developed self-healing Al6061 composite and to optimize the operating conditions for enhanced tribo-performance of the developed material.

Design/methodology/approach

A unique procedure has been adopted to convert the sand casted Al6061 into self-healing material by piercing a low melting point solder material with and without MoS2. Taguchi-based L9 orthogonal array has been used to optimize the number of experiments and analyze the influence of operating parameters such as speed, sliding distance and load on material wear.

Findings

The results reveal that the paper shows the self-healing and self-repair is possible in metal through piercing low melting point alloy. Then, the load has a significant influence over other input parameters in predicting the wear behavior of developed material. Moreover, addition of MoS2 does not affect the tribo-performance of the developed material. The study concludes that the developed self-healing Al6061 has huge potential to be used in mechanical industry.

Research limitations/implications

The concept of self-healing in metals are very challenging task due to very slow diffusion rate of atoms at room temperature. Therefore, researchers are encouraged to explore the other new techniques to create self-healing in metals.

Practical implications

The self-healing materials had shown huge potential to be used in mechanical industry. The current investigation established a structural fabrication and testing procedure to understand the effects of various parameters on wear. The conclusion from the experimentation and optimization helps researchers to developed and create self-healing in metals.

Originality/value

The previous research works were not focused on the study of tribological property of self-healing metal composite. With the best of author’s knowledge, no one has reported tribological study, as well as optimization of parameters such as speed, load and sliding distance on wear in self-healing metals composite.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 5
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 9 April 2018

Shanti Kiran Zade, Suresh Babu V. and Sai Srinadh K.V.

The purpose of this study is to manufacture test boards for re-enacting plant or field situations where vacuum chamber for expelling gas bubbles and autoclave equipment…

Abstract

Purpose

The purpose of this study is to manufacture test boards for re-enacting plant or field situations where vacuum chamber for expelling gas bubbles and autoclave equipment would not be accessible. This research focuses on the examination and enhancement of tensile strength for the nanocomposites consisting of uniaxial glass fiber mats, nanoclay (NC) and epoxy.

Design/methodology/approach

The parameters considered are the weight content of Cloisite 15A NC, the volume of glass fiber (Vgf) and the direction of glass fibers (θ). The composites are made by hand lay-up technique and tested according to ASTM D 638 standard. Taguchi L9 orthogonal array is used to design the experiments.

Findings

The results imply that the orientation of fibers exhibited high significance with a p-value of 0.001 for the upgrade of strength. NC percentage and the volume of fiber have a low effect as the p-values obtained were 0.375 and 0.294. Confirmation tests were performed at the optimal levels of parameters and the outcomes were in the permissible range of the anticipated values of S/N ratio and mean tensile strength. The negligible effect of nanoclay is due to the lack of infusion of resin into the d-spacing of clay layers due to the low configuration settings of mixing conditions which was confirmed by XRD studies. The negligible effect of glass fiber volume is due to the void content and lack of stress transfer between fibers uniformly due to the void content and improper mixing of nanoclay.

Research limitations/implications

The limitation of this study is that a low-speed mechanical stirrer was used to mix NC in the epoxy and the mixture was not subjected to vacuum and ultrasonication for degassing and deagglomeration.

Practical implications

These composites can be used as substitute materials in place of metallic parts in the aerospace and automobile sector. These composites can be used in civil structures instead of steel and concrete, which have low strength-to-weight ratio and where the requirement of strength is in the range of 60 to 390 MPa.

Social implications

The composites can be used in a variety of applications, for example, structural works, automotive panels and low-cost housing.

Originality/value

This research gives an idea about the combined contribution of NC, Vgf and “θ” to the improvement of tensile strength of the glass-epoxy composite.

Details

World Journal of Engineering, vol. 15 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 25 April 2022

Suhail Ahmed Manroo, Noor Zaman Khan, Babar Ahmad and Vinayak Malik

Altering the microstructure and developing the surface metal matrix composites (MMCs) in a solid-state by friction stir processing (FSP) has been on trend for the past…

Abstract

Purpose

Altering the microstructure and developing the surface metal matrix composites (MMCs) in a solid-state by friction stir processing (FSP) has been on trend for the past decade. The microstructural modification increases the material properties, which are structure sensitive. The microstructural evolution is highly influenced by the selection of process parameters in FSP. In this study, the effect of process parameters on the microstructure evolution and microhardness of the fabrication of surface MMCs of newly commercialized Mg-ZE41 alloy by the incorporation of different reinforcement particles such as ZrO2, CeO2 and Al2O3 is investigated.

Design/methodology/approach

By making use of Taguchi’s design of experimentation, which recognizes the crucial factors and ascertain their effect on the properties of the material, the optimization of process parameters for this study was done using MATLAB-14 software. The parameters were adopted along with the levels throughout the FSP for the fabrication of different surface MMCs. For each reinforcement particle, two factors at three levels each had L9 factorial design were used to analyse the effect of these factors on the processing result (microstructure, grain refinement and hardness). The two different factors used in this study are tool rotational speed (TRS) and tool traverse speed (TTS) as a part of the full factorial design matrix for different surface MMCs.

Findings

Among all combinations, TRS of 1500 rpm and TTS of 20 mm/min. for ZE41-ZrO2 MMCs and ZE41-CeO2 MMCs were observed as optimum to produce defect-free processed zone along with the high level of grain refinement and hardness, whereas for ZE41-Al2O3 the same was obtained at 1500 rpm TRS and 10 mm/min TTS.

Originality/value

In this paper, the role of process parameters in the development of surface MMCs on newly commercialized Mg-ZE41 alloy by FSP is investigated. The effect of TRS and TTS on microstructure evolution, grain refinement and microhardness is analysed. Hence, in this study, the optimum parameters for the fabrication of surface MMCs of Mg-ZE41 alloy have thus been established.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 11 June 2021

Debashis Mishra and Anil Kumar Das

The purpose of the experimental investigation was to optimize the process parameters of the fused deposition modeling (FDM) technique. The optimization of the process was…

Abstract

Purpose

The purpose of the experimental investigation was to optimize the process parameters of the fused deposition modeling (FDM) technique. The optimization of the process was performed to identify the relationship between the chosen factors and the tensile strength of acrylonitrile butadiene styrene (ABS) and carbon fiber polylactic acid (PLA) thermoplastic material, FDM printed specimens. The relationship was demonstrated by using the linear experimental model analysis, and a prediction expression was established. The developed prediction expression can be used for the prediction of tensile strength of selected thermoplastic materials at a 95% confidence level.

Design/methodology/approach

The Taguchi L9 experimental methodology was used to plan the total number of experiments to be performed. The process parameters were chosen as three at three working levels. The working range of chosen factors was the printing speed (60, 80 and 100mm/min), 40%, 60% and 80% as the infill density and 0.1mm, 0.2mm and 0.3mm as the layer thickness. The fused deposition modeling process parameters were optimized to get the maximum tensile strength in FDM printed ABS and carbon fiber PLA thermoplastic material specimens.

Findings

The optimum condition was achieved by the process optimization, and the desired results were obtained. The maximum desirability was achieved as 0.98 (98%) for the factors, printing speed 100mm/min, infill density 60mm and layer thickness 0.3mm. The strength of the ABS specimen was predicted to be 23.83MPa. The observed strength value was 23.66MPa. The maximum desirability was obtained as 1 (100%) for the factors, printing speed 100mm/min, infill density 60mm and layer thickness 0.2mm. The strength of the carbon fiber PLA specimen was predicted to be 26.23MPa, and the obtained value was 26.49MPa.

Research limitations/implications

The research shows the useful process parameters and their suitable working conditions to print the tensile specimens of the ABS and carbon fiber PLA thermoplastics by using the fused deposition modeling technique. The process was optimized to identify the most influential factor, and the desired optimum condition was achieved at which the maximum tensile strength was reported. The produced prediction expression can be used to predict the tensile strength of ABS and carbon fiber PLA filaments.

Practical implications

The results obtained from the experimental investigation are useful to get an insight into the FDM process and working limits to print the parts by using the ABS and carbon fiber PLA material for various industrial and structural applications.

Social implications

The results will be useful in choosing the suitable thermoplastic filament for the various prototyping and structural applications. The products that require freedom in design and are difficult to produce by most of the conventional techniques can be produced at low cost and in less time by the fused deposition modeling technique.

Originality/value

The process optimization shows the practical exposures to state an optimum working condition to print the ABS and carbon fiber PLA tensile specimens by using the FDM technique. The carbon fiber PLA shows better strength than ABS thermoplastic material.

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